Let's make sure issue is not already fixed in latest builds first.

• I verified I can reproduce this issue against Eclipse 2025-06 (https://download.eclipse.org/eclipse/downloads/)

Steps to reproduce

From a fresh installation and clean workspace:

• I open the debug configuration
• Create a new configuration (for example Eclipse Application) and save clicking in Apply button
• Modify the name of the same debug configuration
• Click on "new launch configuration"
• A Pop up ask for saving the first config -> click on save

I expected: the first config is saved and the new config can be editing

But got: the first config is saved but I got this error message and the new configuration has not been created

Here is some relevant log output

There is no exception in the console

Tested under this environment:

• OS & version: Windows 10
• Eclipse IDE/Platform version (as shown in Help > About): Version: 2025-06 (4.36.0) - Build id: 20250605-1316 2021-09 (4.21) and maybe even earlier, I didn't look further (@fedejeanne, see Error when changing the name of a new Debug Configuration #2003 (comment))

Community

• I understand reporting an issue to this OSS project does not mandate anyone to fix it. Other contributors may consider the issue, or not, at their own convenience. The most efficient way to get it fixed is that I fix it myself and contribute it back as a good quality patch to the project.